Purpose: Light intensity detected light level sensors, optical module Smart car search Module Features: 1, using the sensitive type photosensitive resistance sensor 2, the comparator output signal clean waveform is good, driving ability, than 15mA. 3, with adjustable potentiometer can adjust the brightness of the light detected 4, Working voltage 3.3V-5V 5, the output format: Digital switching output (0 and 1) 6, with bolt holes for easy installation 7, a small board PCB size: 3.2cm x 1.4cm 8, using a wide voltage LM393 comparator Module for use 1, the photosensitive resistor module most sensitive to ambient light, generally used to detect the brightness of the ambient light, triggering microcontroller or relay modules; 2, the module brightness of ambient light reach the set threshold, DO-side output high when the ambient light level exceeds the set threshold, DO-ended output low; 3, DO output can be directly connected with the microcontroller through the microcontroller to detect high and low, thereby detecting changes in ambient light intensity; 4, DO OUR outputs can directly drive the relay module, which can be composed of a light control switch. Product structure and wiring diagram Open circuit, a friend in need can refer to the following figure SCM test procedure / ****************************************** Shenzhen Electronics Co., Ltd. Yu Song Toyokawa Sensors trigger test SCM: STC89C52 Baud Rate: 9600 Usage: light detection. ***************************************** / include unsigned char date; define uchar unsigned char define uint unsigned int sbit key1 = P0 ^ 1; / * Function declaration ---------------------------------------------- - * / void delay (uint z); void Initial_com (void); / / ************************************************ *********** / * ************************************************** ****************************** * Function Name: delay (uint z) ** Function: Delay function ************************************************** ****************************** * / void delay (uint z) { uint i, j; for (i = z; i> 0; i -) for (j = 110; j> 0; j -); } / / ****************************** / / ***** Serial port initialization function *********** / / ****************************** void Initial_com (void) { EA = 1; / / enable interrupts ES = 1; / / allow the serial port interrupt ET1 = 1; / / Enable timer T1 interrupt TMOD = 0x20; / / Timer T1, an interrupt is generated baud rate in Mode 2 PCON = 0x00; / / SMOD = 0 SCON = 0x50; / / Mode 1 by timer control TH1 = 0xfd; / / set to 9600 baud TL1 = 0xfd; TR1 = 1; / / open the run control bit Timer T1 } / / ************************* / / ********** Main function ********* / / ************************* main () { Initial_com (); while (1) { if (key1 == 0) { delay (); / / eliminate jitter if (key1 == 0) / / Confirm trigger { SBUF = 0X01; delay (200); } } if (RI) { date = SBUF; / / microcontroller to accept SBUF = date; / / microcontroller sends RI = 0; } } }